In order to reduce noise and vibration, a sound insulation structure and a vibration insulation structure, which are respectively configured to damp noise and vibration, are provided in an indoor space of a building, an interior space of an automobile, a road, or the like.
With respect to the sound insulation structure, NPL 1 and NPL 2, for example, disclose a structure of double glazing glass used for a window and the like installed at an interior of a building. In the structure disclosed in NPL 1 and NPL 2, a micropore perforated panel, in which micropores are pierced, is arranged on one surface of the double glazing glass to insulate sound incident from the side of the micropore-perforated panel. In addition, PTL 1 and PTL 2 disclose a structure for absorbing sound incident from an indoor space that is a sound field. In the structure disclosed in PTL 1 and PTL 2, the micropore-perforated panel is arranged such that the obverse surface thereof faces the indoor space that is a sound field, and the reverse surface thereof faces a wall or a ceiling. Furthermore, an air layer is formed between the micropore-perforated panel and the wall or the ceiling, and a plurality of tubular members is arranged on the reverse surface of the micropore-perforated panel for each of the plurality of perforations of the micropore-perforated panel.
With respect to vibration and noise that are problems relating to, in particular, a structure of a building, a load, such as an impact, is applied to a structure of a building due to a behavior of a person existing in the building. Furthermore, vibration may occur based on this impact, and then the vibration may cause solid borne sound (i.e., floor impact sound). PTL 3 discloses a structure of a ceiling and a wall that insulate floor impact sound particularly applied from an upper floor of a building. In the structure of the wall and the ceiling disclosed in PTL 3, a perforated board is arranged on the side of an indoor space of a frame that is the base having a clearance from the frame, an air layer is provided between the frame and the perforated board, and a support member that is made of a rigid material, is arranged between the perforated board and the frame so as to support the perforated board.
In addition, in order to reduce vibration that may occur due to a load applied to a structure of a building, a double structure is conventionally employed for a floor structure of an interior of a building. In the double structure, a floor member is arranged such that the obverse surface thereof faces the side of the indoor space and the reverse surface thereof faces a frame that is the base, an air layer is formed between the floor member and the frame, and the floor member is supported by a vibration proof rubber arranged between the floor member and the frame. NPL 3 discloses a method for changing floor impact sound that may occur due to a load applied to a structure of a building by changing the thickness of an air layer in the double structure described above.